package javaEE;
import java.util.Scanner;
import java.util.Random;
public class test01 {
    public static void main(String[] args) {
        Scanner a=new Scanner(System.in);
        String c="ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz";
        String d="";
        Random b=new Random();
        for (int i = 0; i < 4; i++) {
            int f=b.nextInt(c.length());
            char e=c.charAt(f);
            d+=e;
        }System.out.println(d);
    }
}
